How do you plan "grand tour" missions ?

[lyndonguitar]

I want to do some Voyager Like missions, going planet after planet without using alot of delta-v thanks to gravity assists. can you properly plan out such missions in KSP without so much computations?

[Flixxbeatz]

My theoretical plan for stock grand tour missions involve refueling spacecrafts. lots of them.

Plan includes launching and placing refueling spacecrafts into the planets and moons you plan to visit before starting the mission. The number of refuelers on each destination should be enough to fully top up your grand tour craft before landing/heading to the next destination/both.

For a whole kerbol system flyby (all of the planets and moons), it won't pose a problem (you can even land on places that has low enough gravity), but if you want to land on everything in one and go back in one piece, that would be another story.

I have only thought of this, and yet to try them in action.

Edited January 19, 2014 by Flixxbeatz

[Sauron]

Refueling ships kind of defeat the spirit of a grand tour

Some suggestions:

-Aggressively stage LV-Ns--you need less DV for your transfers than you think you will, and staged LVNs provide more than enough.

-Aerobrake where possible.

-Gravity assist where possible--a roundabout route that uses Eve, Kerbin, and Jool well will save a lot of DV (if not time)

-As much as possible, make one lander that can handle everything, and that gradually gets smaller as you need it to.

-Since Eve will probably require a very large dedicated lander, you want to go there first so you're not lugging that deadweight around. Everywhere else can be done with the same lander.

[Flixxbeatz]

Refueling ships kind of defeat the spirit of a grand tour

Dammit, I got it wrong again *sigh*

But I think that going in each body, landing, going back to space again, and without even refueling at some point even once is impossible, unless you have a hardware strong enough to let you build a craft massive enough to haul all the fuel you need

But that's just me.

[thereaverofdarkness]

You can wait for a launch window and go to that body, then when you're finished there, wait for another launch window.

[Soda Popinski]

A Voyager style Grand Tour would be doable without refueling, because the Voyager spacecraft never landed.

I would use the Kernan Launch Window calculator to figure out when to head out to, say Duna, then look at your arrival time, replug that in for a Jool intercept. Trial and error, as the timing must be right for everything to line up.

[regex]

It takes a lot of planning. If you just want to do a Voyager type fly-by (just as awesome an achievement IMO), this tool should help:

http://forum.kerbalspaceprogram.com/threads/36476-WIN-KSP-Trajectory-Optimization-Tool-v0-11-2-Now-with-Mission-Control-Center%21

If you're planning on landing everywhere you'll want to send certain landers ahead (Eve, Tylo, and maybe Laythe will require special landers) and you'll probably also want refueling ships (IIRC at most you can get 17km/s out of a craft in KSP without Ion engines). All of those ships will be sent out on a schedule so Kerbal Alarm Clock would be a good mod to get. Dpending on your strategy you could go for a short tour (my initial route was a bit over five years) or for the long haul with optimized trajectories and minimal delta-V expenditure (if you want to send as few refuelers as possible). Using the Kethane mod would allow you to refuel in situ, making the entire affair easier. It also allows you to do an all-in-one tour craft (although you may not be using it for landing on Eve...)

Or you could do the whole thing with a command chair and ions for your main craft, which is a bit unrealistic but impressive nontheless.

[Sauron]

I have seen 1-ship, no refueling grand tours before. It's very much possible! Gravity assists are mandatory though Ideally you want to use one very bare-bones lander that sheds parts as needed.

Personally, I would consider sending the Eve lander separately to be very reasonable--an almost-grand-tour is still an achievement.

Edit:

That 17k DV limit is for single-stage LV-Ns. You can do much, much better by staging.

Edited January 19, 2014 by Sauron

[Mobjack]

The Kebol System doesn't enough massive planets to make a good grand tour. There should be at least two big planets outside of Jool to pull it off well and you would have to wait for the planets to align.

You can work on using gravity assists from Eve, Jool and Kerbin to get to other planets with minimal dV, but that requires lots of patience and trial by error.

[Sauron]

The Kebol System doesn't enough massive planets to make a good grand tour. There should be at least two big planets outside of Jool to pull it off well and you would have to wait for the planets to align.

You can work on using gravity assists from Eve, Jool and Kerbin to get to other planets with minimal dV, but that requires lots of patience and trial by error.

It works passably well. The trick is to double down on your gravity assists at Eve (especially). Obviously a bigger system would make for a more exciting grand tour.

Also: as a point of interest, I've just made an 18-ton universal (except Eve and including Kerbin) lander. It's SSTO everywhere except Tylo. So the optimal flight plan would involve Eve first (to dump a larger Eve lander as soon as possible) followed by Laythe, then Tylo where the outer stages are ditched. At that point it doesn't particularly matter where you go next since the core stage can land and return on every other body in the Kerbin system, but aiming for fuel-intensive places first is probably wise).

[StevenLawyer]

Here's my single launch, no refuel, stock grand tour ship that includes a reusable lander for all planets except Eve (Eve is a separate one time use lander), including Tylo with reusable rover and reusable probes (you're not going to land on a planet without first sending an unmanned probe, are you?). I finished the mission with fuel to spare.

[Claw]

StevenLawyer,

If you'd like to post a mission report or tutorial, please check those areas to see which your video might fit into better. I'm going to close this thread since the question is either answered or long since irrelevant.

Nice looking craft though.

Cheers,

~Claw